Re: timing belt

[JustaxPHX@aol.com]

>> paul W said ..line up the mark on the lower pulley with the mark on the
>> timing belt cover...this does _not_ always work!! on my 5kcdtq the mark on
>> the lower pulley was so far off it pointed to the centre of the idler wheel
>> bolt. i verified tdc with a brass rod in the sparkplug hole of #1, the "0"
>> on the flywheel, and the dimple on the camshaft. once happy that all was
>> well, i marked the lower pulley correctly.
>
>If I found one that didn't match here, I'd take the harmonic balancer
>off and check that the key hasn't broken off the timing belt cog.
>The harmonic balancer is keyed to the cog too

There's another possibility to consider as well; namely, that the harmonic 
balancer on your car isn't the original one that came with it and/or was 
designed to use or that's it failed.

I know this because the timing notch on the harmonic balancer on my '89 200q 
points in exactly the same direction as referred to above and mine was 
originally installed on an '87 5k with an NF motor.  When I backdated to the 
early-style cam pulley from the later "high-torque" version -- this so I 
could use the adjustable sprocket I had lying around -- I used the harmonic 
balancer from my wrecked 5k instead of the one I'd plucked off a wrecked 5ktq 
at a salvage yard because that one turned out to have a buggered keyway that 
somehow slipped past my pre-purchase quality control inspection.

Anyway, both balancers weighed virtually the same and when I checked the 
rubber hardness using my durometer, this was virtually the same as well so I 
figured they were close enough in spec to be interchangeable.  The only 
difference I could find was that the timing notches were located in different 
positions but since I prefer to align the sprockets using dial indicators 
instead of the factory's TDC marks, this was only a minor inconvenience.

Of course, it's also possible the balancer has been damaged and the outer 
section has rotated around the inner section ... although I've never heard of 
it happening to an Audi, it does sometimes happen on Detroit V8s.

JG